Georgia Septic Installer Practice Test

What material must cover the pipes in a pressurized system?

1. Sand

2. Aggregate

3. Clay

4. Gravel

The correct answer is: Aggregate

In a pressurized septic system, using aggregate material to cover the pipes is essential for proper drainage and effective operation. Aggregate consists of various sizes of stones or gravel, which create voids within the material, allowing for improved water permeation. This facilitates the movement of effluent from the pipes to the surrounding soil, ensuring efficient filtration and reducing the risk of clogging. Additionally, the use of aggregate promotes aeration and helps maintain the structural integrity of the soil environment, which is vital for the overall functioning of the septic system. Proper coverage with aggregate also aids in protecting the pipes from external pressures, which is important for maintaining system reliability and longevity. The other options do not provide the same level of support for drainage and filtration. Sand may retain too much moisture, leading to reduced permeability and increased risk of backup. Clay is extremely dense and has low permeability, making it unsuitable for covering pipes as it could lead to stagnant effluent. Gravel, while it provides good drainage, does not serve the optimal balance of stability and filtration that aggregate does in a pressurized system. Thus, aggregate is the best choice for covering pipes effectively.